400 + 68 = 468 .
How about adding 598 and 78 ?
Add 2 to 598 to make it whole 600, making the addition simpler. Since 2 more is added, subtract 2 from the sum to get the final answer.
598 + 78 = ?
600 + 78 - 2 = 676
More examples:
44 + 19 = ?
44 + 20 - 1 = 63
97 + 86 = ?
100 + 86 - 3 =183
994 + 678 = ?
1000 + 678 - 6 = 1672
Same goes with subtraction. Subtracting 20 from 46 is as easy as
46 - 20 = 26 .
How about subtracting 18 from 54 ?
Add 2 to 18 to make it 20. Since 2 more is subtracted, add back 2 to get the final answer.
54 - 18 = ?
54 - 20 + 2 = 36
More examples:
444 - 198 = ?
444 - 200 + 2 = 246
55 - 29 = ?
55 - 30 + 1 = 26
875 - 496 = ?
875 - 500 + 4 = 379
#Matamata
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